littelfuse.com© 2020 Littelfuse Revised: BO.12/07/20
Specifications are subject to change without notice.
Electrical Ratings
Contact Rating 1W/VA - max. 10
Voltage 3
Switching 2
Breakdown 4
Vdc - max.
Vac - max.
Vdc - min.
200
140
200
Current 3
Switching 2
Carry
Adc - max.
Aac - max.
Adc - max.
0.50
0.35
1.00
Resistance Contact, Initial
Insulation
Ω - max.
Ω - min.
0.100
1010
Capacitance Contact pF - typ. 0.3
Temperature Operating
Storage 5
°C
°C
-40 to +125
-65 to +125
MASM-14 14mm Close-Differential Reed Switch
Description
The MASM-14 surface mount reed switch is a close-differential, sub-miniature,
normally open switch with a 14mm long x 2.28mm diameter (0.551” x 0.090”)
glass envelope, capable of switching 200Vdc at 10W.
This reed switch is a surface mount version of MACD-14. It has high insulation
resistance of 1010 ohms minimum and a contact resistance of less than 100
milliohms. Both reed switches are intended for use in applications that require
low hysteresis between Pull-In and Drop-Out values.
Agency Approvals
Agency Agency File Number Ampere-Turns Range
E47258
E471070 10-30 AT
Switch Type
Contact Form A (SPST-NO)
Materials Body: Glass
Leads: Tin-plated Ni-Fe wire
Surface Mount Reed Switches
Features
• Surface mount normally open
switch
• Capable of switching 200Vdc or
0.5A at up to 10W
• Low close/open hysteresis (close
differential)
Benefits
• Hermetically sealed switch
contacts are not affected by and
have no effect on their external
environment
• Zero operating power required for
contact closure
• Excellent for switching micro-
controller logic level loads
Applications
• Position Sensing
• Level Sensing
• Security
• Industrial Controls
• Office Equipment
• Home Appliances
Dimensions
Dimensions in mm (inch)
Low Power > MASM-14
RoHS
Note: SPST-NO = Single-pole, single-throw, normally open
Note: Land pattern is Littelfuse recommendation only. User is responsible for proper PCB design.
Ø2.28 MAX
(.090) 2x1.14±0.10
(.045±.004)
17.52±0.25
(.690±.010)
19.30±0.25
(.760±.010)
2x0.00 MIN
2x3.05 (.120)
2x1.65 (.065)
(.000)
14.60
(.575)
2.84 MAX
(.112)
14.00 MAX
(.551)
RECOMMENDED LAND PATTERN
Notes:
1. Contact rating - Product of the switching voltage and current should never exceed the wattage rating. Contact Littelfuse for additional load/life information.
2. When switching inductive and/or capacitive loads, the effects of transient voltages and/or currents should be considered. Refer to Application Notes AN108A and
AN107 for details.
3. Electrical Load Life Expectancy - Contact Littelfuse with voltage, current values along with type of load.
4. Breakdown Voltage - per MIL-STD-202, Method 301.
5. Storage Temperature - Long time exposure at elevated temperature may degrade solderability of the leads.
Note: Contact Littelfuse for specific agency approval ratings.
littelfuse.com© 2020 Littelfuse Revised: BO.12/07/20
Specifications are subject to change without notice.
Magnetic Characteristics
Pull-In Range 3Ampere Turns 10-15, 15-20, 20-25, 25-30
Rating Sensitivity 4Ampere Turns 20
Test Coil L4989
Drop-Out vs. Pull-In Chart
Packaging
Packaging Option Packaging Specification Quantity Quantity & Packaging Code Taping Width
Tape and Reel EIA-RS-481-1 3000 R 32mm
Product Characteristics
Operating Characteristics
Operate Time 10.6ms - max.
Release Time 10.2ms - max.
Shock 211ms 1∕2 sine wave 100G - max.
Vibration 250-2000 Hertz 30G - max.
Resonant Frequency 5.3kHz typ
Part Numbering System
Notes:
1. Operate (including bounce)/Release Time - per EIA/NARM RS-421-A,diode suppressed coil (Coil II).
2. Shock and Vibration - per EIA/NARM RS-421-A and MIL-STD-202.
3. Pull-In Range - Contact Littelfuse for narrower AT ranges available. These AT ranges are the before modification AT of the MACD-14.
4. Rating Sensitivity - The value at which contact ratings and operating characteristics are determined. Derating may be required below this value.
MASM-14 R - 10-15
Series
AT Range
10-15 AT
15-20 AT
20-25 AT
25-30 AT
Packaging
R = Tape and Reel
Surface Mount Reed Switches
Low Power > MASM-14
MASM-14 14mm Close-Differential Reed Switch
Note:
Chart represents the range of Drop Out, min to max for a given Pull-In value of
the MACD-14 prior to modification into the MASM-14.
5
0
10
15
20
25
50
Pull-In (AT, L4989 Coil)
Drop-Out (AT, L4989 Coil)
10 15 20 25 30
35
Max.
Min.
littelfuse.com© 2020 Littelfuse Revised: BO.12/07/20
Specifications are subject to change without notice.
TAPE DIMENSIONS mm (inch)
REEL DIMENSIONS mm (inch)
MASM-14 14mm Close-Differential Reed Switch
Surface Mount Reed Switches
Low Power > MASM-14
